The Transmission of Electrons through Metallic Foils

Abstract

Electron transmission measurements, using a collecting cup and galvanometers, have been made for homogeneous energy beams in the range 0.25-0.75 MeV in foils of Be, Al, Cu, Ag and Au. The discrepancy between the present measurement of extrapolated range in aluminium and the generally accepted range-energy relationship cannot be simply explained in terms of low energy secondary emission or geometrical effects. Transmission measurements through silver foils agree, however, with other published results. The angular distribution of electrons emerging from the exit side of a foil has been examined. This appears to approach a cosine distribution at low transmissions. Further information on range values, and some confirmation of voltage calibration have been obtained from ionization in depth measurements.